Finishing tool



7 July 14, 1931. E. HOPE 1,814,553

' FINISHING TOOL.

Filed March 51,- I930 Patented July 14, 1931 U ED STATES PATE T OFFICE ERNEST HOPE, OF LEICESTER, ENGLAND, ASSIGNOR TO UNITED SHOE MACHINERY COR- PORATION, OF PATERSON, NEW JERSEY, A CORPOR-ATION OF NEW JERSEY FINISHING ,TOOL

Application filed March 31 1930, Serial No. 440,366, and in Great Britain April 12, 1 929.

This invention relates to finishingtools and is herein illustrated as embodied in a finishing tool of the-general type disclosed in my application for United StatesLetters Patent Serial No. 357,561, filed April 23, 1929.

Tools of the type under consideration may advantageously beem'ployed for the buffing, polishing or other finishing treatment of relatively small areas having curved or irregular shapes, as, for example, in the scouring of the curved breast surfaces of Louis heels. The tool disclosed in the application above mentioned' and the. tool illustrated herein have certain features in common; namely, each consists ofa disk of 'yieldable material such as rubber and is adapted to carryon its periphery a finishing cover in the form of a band of abrasive material, the disk being subject to expansion by centrifugal force when rotated and thereby tending toexert an outward pressure to grip the abrasive band. In the tools disclosed in both this and the above-mentioned application the disk is so supported that it can yield both radially and'laterally; but inasmuch as this feature is claimed in the abovementioned application it will not be claimed herein.

An object of this invention is to provide an improved finishing tool of relatively cheap and simple c'on's'truction, o

In accordance with thisobject, one feature of the invention "resides in the provi-. sion of'a disk of yieldable material of dished form, the disk being intended to carry upon its periphery a finishing cover and to grip the finishing cover as the disk tends to increase its diameter under the centrifugal effect of rotation. As in'the illustrated construction, the disk is composed of material which isnormally flat, and is maintained in a dished condition by the employment of means designed to that end. It is believed that the tendency, above referred to, of the disk to increase its diameter upon rotation is greater for a disk composed of normally flat material distorted into a dished form than it would be for a-disk molded in dished form. The same means for maintaining the disk in its dished condition may advantageously be employed to secure the disk upon a shaft, and consists, in the illustrated machine, of a collar mounted on the shaft and having a centrally recessed face, and of means for clamping the disk against the recessed face of: the collar with the central portion of the disk forced into thecentral recess of the collar. By locating the above mentioned disk-securing means close to one end of the shaft, interference by the shaft or by the securing means with the work as the latter is manipulated in various positions of presentationto the finishing cover may be avoided. k

' In accordance with another feature of the invention, the disk is formed with a laterally rounded periphery, and the-finishing cover, consisting of a band of abrasive material, is narrower than the thickness of the disk and-is molded to have a lateral curvature of a radius less than the radius of lateral curvature of the periphery of the disk. Anadvantage of this construction is that the edges of the abrasive cover tend to become embedded in the material of the disk and are thus prevented from scratching the work.

These and other features of the invention including certain details of construction and combinations of parts will be described in combination with an illustrative tool and pointed out in the claims. I Referring now to the accompanying draw- Fig.1 is a side View, partly in section, of a tool and a finishingcover embodying the invention. I

The tool illustrated inFig. 1 comprises a soft rubber disk or bed 1 some four and a' threaded to receive the nut 2. The spindle, collar, disk and nut are coaxial. The end face of the collar 4 against which the disk 1 is clamped has a cone-shaped recess 7 (coaxial with the collar) into which the centre part of the disk 1 is forced by the nut 2 and Washer 3, the disk being normally flat, and is in this manner deformed or distorted to assume a dished or somewhat conical shape,-'the centre of the outer face of the disk being then bulged and being displaced or offset from the plane of the periphcry of the face by about three-quarters of an inch, and the threaded end of the spindle 6 and the outer face of the hut 2 then lying some one quarter of an inch tothe same side of this plane as the centre of said face of the disk 1. Amolded abrasive band 8 which may be similar to thatdescribed in the aforementioned specification is placed on the periphery of the disk. The abrasive band 1s preferably, however, not quite so wide as the disk is thick and is molded so that the radius of the lateral curvature of the inside face of the band is slightly less than the radius of the edge of the disk; The disk 1 in its normalcondition is too large to fit the band 8. The deforming of the disk in the manner above described diminishes the diameter of the periphery of the disk, and the abrasive band 8 is of such a diameter that,- when the disk is clamped against the recessed face of the collar and thereby distorted as aforesaid, it can just be threaded readily on the disk. hen the spindle is rapidly rotated, say at 3000 R. P. M., the rapidly rotating disk 1 under centrifugal action tends to flatten itself and increase its diameter, thereby gripping the abrasive band 8 firmly, and if the abrasive band is of the second form above described its edge will be slightly bedded into the disk and thus prevented from scratching or marking the work in an undesired manner. In the preferred form of tool the band is of such a diameter that the disk does not, when rapidly rotated, ever quite flatten out but always remains somewhat dished. The depth of the depression at one side of the disk 1 caused by the dishing, the flexibility of the disk, the speed and the diameter of the band 8 are preferably such that the end of the spindle 6 and the nut 2 do not,- even when the tool is rotating, project beyond the plane of the periphery of the outer face of the disk appreciably, if at all, this arrangement being advantageous in allowing sharply curved portions of work-pieces to be presented to the tool and manipulated without any part of them coining into contact with the side of the disk itself or the nut or spindle.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is 1. A finishing tool comprising a disk of yieldable material adapted to carry upon its periphery a finishing cover, said disk being of dished form whereby upon rotation it will tend, because of centrifugal action, to increase its diameter and thereby to grip the finishing cover.

2. A finishing tool comprising a disk of normally fiat yieldable material adapted to carry upon its periphery a finishing cover, and means for maintaining said disk in a dished condition whereby upon rotation said disk will tend, because of centrifugal action, to assume its normal form and to increase its diameter, thereby gripping the finishing cover. W V H I,

3; A finishing tool comprising a, disk of yieldable material adapted to carry upon its periphery a finishing cover, and means for securing said disk axially upon a shaft, said securing means being constructed and arranged to effect a relative axial displacement between the central and the peripheral portions of said disk to diminish the 'diameter of the periphery of 'said disk,- said disk tending upon rotation to expand centrifugally to grip the finishing cover. t 4.- In combination,- a disk of yieldable material, a band of finishing material adapted to be carriedupon the periphery of said disk, said disk in its normal condition being too large to fit said band, and means for deforming said disk.to diminish the diameter ofthe periphery of said disk to enable said bandtobe mounted upon the pe riphery of said disk. i .t 5. In combination, a disk of yieldable material, a band of abrasive material adapted to be carried upon the periphery of said disk, said disk in its normal condition being too large to fit said band, and means for securing said disk axially upon a shaft, said securing means being constructed and arranged to effect a relative axial displacement between the central and the peripheral portions of said disk to diminish the diameter of the periphery of said disk to enable said. band to be mounted upon the peripheryof said disk, and said disk tendmg upon rotation to resume its normal condition and thereby to exert outward pressure upon said band of abrasive material.

6. In combination, a disk of yieldable material adapted to carry upon its 'perip'hery an abrasive cover, a shaft, a collar material adapted to carry upon its periphery a finishing cover, a shaft having a free end, and means for securing said disk upon said shaft with the peripheral portion of the disk displaced relatively to the central portion in an outward and axial direction withrespect to the shaft a distance sufiicient to bring the plane of the periphery of the outer face of the disk beyond the free end of said shaft and beyond said securing means, thereby avoiding interference by the shaft or by the securing means with a work-piece to be treated.

8. In combination, a rubber disk adapted to carry upon its periphery an abrasive cover, a shaft having a free end, a collar mounted upon said shaft adjacent to the free end of said shaft, the outer face of said collar belng centrally recessed, and means for clamplng sa d rubber d1sk agalnst the outer face of said collar with the central portion of the diskforced into the central recess of the collar and with the plane of the periphery of the outer face of the disk extending beyond the free end of the shaft and beyond said clamping means, thereby avoiding interference by the shaft or by the securing means with a Work-piece in various positions of presentation to said abrasive cover.

9. In combination, a disk having a laterally rounded peripheral portion of yield able material, an abrasive band narrower than the thickness of said disk mounted upon the periphery of said disk, said abrasive band being molded to have a lateral curvature of a radius less than the radius of the lateral curvature of the periphery of said disk, said disk being constructed and arranged to expand when in use to cause the edges of said abrasive band to tend to become embedded in the material of said disk.

In testimony whereof I have signed my name to this specification.

ERNEST HOPE. 

